Mobile devices such as a smartphone, a tablet PC and the like have been developed remarkably after the development of standing devices such as a personal computer (PC), a television (TV) and the like.
The standing device and the mobile device have been developed individually in their own fields, respectively. Yet, a boundary between the two regions becomes blurred recently according to the boom of digital convergence.
As user's expectation rises according to the development or environmental change of such a digital device, there are many requests for supporting various services or applications of high specifications.
Recently, a digital device is evolved into a video wall display consisting of a multitude of display panels to meet the needs for a large screen.
Yet, in a digital device such as a video wall display, as an image of a different color sense is displayed on each display panel, it causes a problem that the color senses should be harmonized.
So, in order to harmonize the color senses of the display panels, the digital device performs auto-calibration using a sensor or camera scheme.
Here, the sensor scheme indicates a scheme of attaching a sensor to a point of a screen and applying a value obtained from the point to a whole screen collectively. The camera scheme is a scheme of recognizing a display region, calculating an average value of the region, and applying the average value to a whole screen collectively.
However, according to the sensor scheme, if display panels are manufactured by different manufacturers, it is difficult to harmonize the color sense of a whole screen. According to the camera scheme, since it is unable to give a different color sense per region of a screen, it causes a problem that an overall white balance is not uniform.
Moreover, as a color value measured by a sensor, a camera or the like is different from a color value actually meeting a person's eye, it causes an inconvenience that a color value should be adjusted per display panel one by one.